The primary objective of the Physiology Core is to provide DRC members with access to centralized facilities, services and technical expertise to address complex metabolic questions related to diabetes using normal, diabetic or genetically modified rodent models (including rats, and in some cases mice). This fee-for service Core consists of two Sub-cores, the Animal Surgery and Experimental Procedure Sub-core and the Analytical Sub-core, each of which contains specialized equipment and key personnel to help DRC investigators and/or their trainees achieve their tasks in the most efficient and cost-effective manner. It also serves as a forum for collaboration between members with different research backgrounds but a common interest in studying diabetes. Through the Animal Surgery and Experimental Procedure Sub-core, DRC investigators can access training courses, equipment, laboratory facilities and technical expertise to perform surgeries for stereotaxis and the placement of vascular catheters and other implantables, as well as carry out complex metabolic studies using specialized experimental methodologies (e.g. glucose clamps, tracers, microdialysis and amperometric studies) in conscious rodents - skills that are not easily accessible to investigators without previous training or experience. The Analytical Sub-core provides DRC members with a central facility for the measurement of glucoregulatory hormones, cytokines and neurotransmitters derived from the animal studies. This component of the Physiology Core benefits from the expertise and equipment of an on-going and prolific radioimmunoassay and HPLC facility which has recently incorporated Luminex technology and tandem mass spectrometry for measuring cytokines and neurotransmitters, respectively. In addition, DRC investigators can now profile a focused panel of genes using PCR array technology through this sub-core. Together, these two sub-cores provide DRC members with the unique opportunity to systematically address pertinent mechanistic questions in vivo and to assess metabolic changes in both the central nervous system and peripheral tissues in the most efficient and economical manner.